Direct-current vibratory motor



L. R. MCDONALD.

DIRECT CURRENT VIBRATORY MOIOR.

APPLICATION FILED DEc.2a. 191e.

1,396,336. Patented Nov. 8, 1921.

E?, mi2/res WA4/m AUNITED STATE-s PATENT OFFICE.

LESLIE It. M'enoNALn, Aor MONTREAL, QUEBEC, CANADA, AssIGNon ToMARGUERITE v. oLEAnY, or MONTREAL, QUEBEC, cANAnA.

DIRECT-CURRENT vIBBA'roaY Moron Application med December 2, 191e.- sermiNo. 139,334.

To-aZZ whom it may concern:

Be it known that I, LESLIE R. MDONALD, a citizen of the United States,and resident of Montreal, in the Province' of Quebec and Dominion ofCanada, have invented new and useful Improvements in Direct-CurrentVibratory Motors, of which the following is a specification.

This application ism `part a continuation of my prior application'filedJune 16, 1916, S.' N. 104,095.

The p "cipal object of this invention is to adapt a motor of the generalcharacter referred to to be operated with direct cur-` rent. Anotherobject ofthelinvention is to vprovide means for intei'pting the directcurrent at the proper frequency and time intervals continuously tovibrate tlie vibratory members. Another object is to provide avpluralityof means for interrupting the current, the meansv being sofassociatedtogether that they may be operated either separately or inconjunctiontoopen and close the circuit at the proper intervals of timeYwith respect to the `vibration of the vibratory members. Another objectof the invention is to employ the vibratory members for controlling theapplication of the recurrent force driving the members. A further objectis to employ vibratory means tuned to vibrate in synchronism with thevibratory members for controlling the application of the recurrentforce. And still a further object is to associate the vibratorycontrolling means with the means for driving the vibratory members ofthev motor so that both the vibratory means and the vibratory membersare driven by the same means.

Other objects of the invention will be apparent from the followingdescription taken with the accompanying drawings in which- Figure 1 is aplan view of one embodiment of the invention;

Fig. 2 is a vertical longitudinal section taken on line 2 2 of Fig. 1; y

Fig. 3 is a left end view of the apparatus; and

Fig. 4 is a diagram illustrating one system of circuit connections forthe apparatus.

The particular embodiment of the invention illustrated in the drawingscomprises vibratory members 1 arranged in the form of' i Specication ofLetters Patent.

Patented-Nov. s, 19.21.

end 2 of the supporting frame 3 by means of machine screws 4. Thevibratory members 1 preferably comprise two straps of metal, an outerstrap 8 of magnetic material and an inner strap 9 of non-magneticmater1al, the two straps being brazed or otherwise connected together,preferably only at their freeends. The members are ada ted `to bevibrated by means of a field coil 11 surrounding an armature 12 which ismount ed on the struck-up Vportions 13 of the frame 3. The faces 14 ofthe armature 12 are curved, the radius of curvature of each face beingsubstantially equal to the length of the respective vibratory membersand the center of curvature being disposed at the fixed end of thecorresponding vibratory` member so that, as the vibratory?. members moveto and fro along the arcuate faces 14, the air-gaps between thevibratory members and the armature remain substantially constant inlength. By applying a pulsatory current to .the coil 11 a pulsatorymagnetlc uX is set up in the substantially closed magnetic circuitformed by the armature 12 and the magnetic strap 8 of the vibratorymembers. Owing to' the hysteretic eect of the magnetic flux on themagnetic portion 8, the vibratory members may be caused to vibrate backand forth in synchronism with the variations in flux. A A

The means for converting the vibratory energy of the vibratory membersinto rotary motion may, for example, comprise a pulley 16 mounted on ashaft 17 which rotates in the bearing 18 threaded into the opening 19 ofthe frame 3, the upper end of the shaft 17 being provided with screwthreads for connecting the shaft to the apparatus to be driven thereby.A belt 21 is connected at one end to one of the vibratory members 1 bymeans of a hook 22 for example, and at the other end, through the mediumof a coil spring 23, to a bracket 24 mounted on the base of. the tuningfork, the belt contacting with the periphery of the pulley th'rough anangle of Aapproximately 420o intermediate its ends and being heldtightly in contact with the pulley by means of the spring 23. When thevibratory members move to and fro, the belt is reciprocated back andforth, thereby continuously rotating the pulley 16 in the direction ofthe arrow as fully explained in the aforesaid applications.

. circuit between the member 31 andthe end.

A. portion 26 of one side of frame 3 is struck up and an Ainsulatinplate 27 is mounted on its outer face. pon theinsu- --lating member 27isi mounted an electrical contact spring 28 having a contact point onits free end arranged to engage the contact. point 29 mounted on theidle vibratory member 1. When employing contacts 28 and 29 as the soleinterrupting means, the points are arranged to engage each other whenthe vibratory members are in the position. of rest, as illustrated; butwhen employing con-V tacts 28 and 29 in conjunction with otherinterrupting means hereinafter described, the contacts may be arrangedto open and close when the vibratory member is at a position eithersomewhat within or without the position of rest. This contacting meansis preferably associated with the idle vibratory member 1 so that one ofthe vibratory members is employed to drive the rotary member and theother vibratory member is employed to open and close the supply circuitin .synchronism with the vibration of the members, the two ends of thetuning fork vibrating in synchronism when they have approximately thesame period of vibration.

Additional interrupting means comprising contacts 31 and 32 arepreferably mounted on an insulating plate 33 which in turn is secured tothe upturned end 34 of frame 3 by means of machine screws 35. Contact 31is in the form of a spring mounted on the angular magnetic member 36 andarranged to vibrate between contact 32 and stop 37, the stop 37 beingmounted on an angular magnetic member 38 similar to 36. The contact 32is preferably threaded through a .spring member 39 which is mounted onthe insulating plate 34 by means of a binding post 41. The fixed end ofthe vibrating spring 31 is connected to a binding post 42 throughconductor 43. The spring 31 is preferably tuned to vibrate insynchronism with the vibratory members 1.

The angular magnetic members 36 and 38 are mounted on the ends ofinsulating plate 33 by means of machine screws 40 so that the ends ofthemembers extend into contact with or `at least into immediate proximitywith the armature 12. A shunt magnetic circuit is thus provided whichconsists of the magnetic members 36 and 38 and the vibratory member 31.Member 31 is arranged normally to contact with contact 32, thus leavinga gap in the shunt magnetic of member 38. As magnetic iiux is directedthrough this shunt circuit by` current flowing in coil. 11, the spring31 tends to move outwardly to close the aforesaid gap in the shunt, andin moving outwardly opens the circuit at contact 32. When the clrcuit isopened the electro-magnet 11 is denergized, the ux dies out, and thespring 3l springs back into contact with screw 32, this action beingcontinued in synchronism with the vibrations of the vibratory membersproduced by the electromagnet 11. In this connection it is to be notedthat the frame 43 may be formed of non-magnetic material, such as brassor hard rubber, if it is desired to avoid shunting the armature -12through the portions 13 ofthe frame.

A suitable circuit arrangement for the apparatus -is that shown in Fig.4, wherein the supply conductors 50 are connected to the electromagnet11 through the medium of a circuit comprising two branches 52 and 53.The branch 52 is provided with a switch 54 and includes the vibratingcontacts3l and 32 illustrated in Figs. 1, 2 and 3. The branch 53 isprovided with a switch 55 and includes the contacts 28 and 29 shown inFigs. 1 and 2. The branch circuit joins at point 56 and at point 57, andis shunted by acircuit 58 including a condenser 59 so as to preventsparking at the vibrating cont'acts. By closing switch 54 electromagnet11 is supplied with impulses of current through contacts 31 and 32; whenswitch 55 is closed, the electromagnet is supplied with pulsatingcurrent through contacts 28 and 29; and when both of the switches areclosed, both sets of vibrating contacts may be arranged conjunctively toopen and close the circuit through the electromagnet.

Inasmuch as the vibrating spring 31 is i cuit at time intervals properlytimed with respect to the vibration of the vibratory members, and theother set of contacts is arranged to open the circuit at the proper timeintervals that is the respective sets of contacts are so positioned,tensioned, etc., that one set closes before the other set, and thelatter set remains closed after the first set has opened, there bein aninterval of time between the first opening and the last closing duringwhich both sets of contacts are closed. This affords the advantage thatthe opening and closing times can be more accurately determined whereone set of contacts can be regulated exclusively with respect to thetime of closing,- and the other set exclusively with respect to the timeof opening,.than where a single set must beso adjusted as not only toclose the circuit at the proper instant but also to open it at theproper instant, it being very important to open and close the circuit atthe proper instants to obtain the greatest efficiency in the operationof the motor.

In the o ration of motors of my new type, that 1s, of the generalcharacter disc osed in this application and my copending applicationsabove cited, I have observed that a wave motion is set up throughout thebelt and, especially in larger motors, this wave motion is so ronouncedthat an appreciable space can lie observed between the pulley and thebelt. My experiments lead me to believe that the greatest torque isobtained when the spring is so tensioned as to roduce two nodes, one ateach end of the belt. The waves travel from the end of the beltconnected to the vibratory member toward the opposite end of the belt,that is, toward the end connected to the spring in the disclosedembodiment. If the belt be removed from the pulley and be extended in astraight line in a direction such that it makes substantially the sameangle with the vibratory member as does the portion between the pulleyand the vibratory member in the drawings, the belt may be so tensionedby means of a spring at its free end that either one or more nodesappear when the belt is allowed to be vibrated freely by the vibratorymember.

With the spring tensioned so as to produce a node at each end of thebelt and with the belt extending in a straight line so as to vibrateunobstructedly as above described. the belt bows irst in one directionand then in the other direction from this straight line. As thevibratory member moves inwardly the belt bows upwardly and to the leftin a direction normal to the plane of the belt when at rest; and whenthe vibra-tory member moves outwardly the belt bows downwardly and tothe right in the opposite direction. When the belt surrounds the pulleyas illustrated in the drawings,'this wave motion results in the beltbeing thrown radially outwardly from the pulley as the vibratory membermoves inwardly, whereby it may be reciprocated in a clockwise direction(Fig. l) by the spring 23 practically out of contact with the pulley;and as the vibratory member moves outwardly the belt is reci rocated ina counter-clockwise direction w 'le tightly drawn around the pulley,thereby rotating the pulley in a counter-clockwise direction. With theimpulses occurring at the rate of 120 per second, the angular velocityof the pulley is substantially constant.

The above phenomena appear to be characteristic of the apparatus, and .Ibelieve them to involve important principles governing the operation ofthe subject matter of my set forth is merely thetheory which I believeto be the true explanation of the pheinvention. However, it is to be understood that the theory of operation above nomena which I have observedduring an extended period of operation of apparatus of the characterdescrlbed and that the theory is given merely for the purpose ofdisclosing the invention in the fullest possible manner and it is not tobe construedas lim-` iting the scope of the patent in any manner.

whatsoever.

I claim:

1. Motor apparatus comprising driving means, a vibratory member foroperating the driving means, electroma netic means for vibrating saidmember, an a second vi- Vbratory member vibrating separately from neticmeans Jfor oscillating the oscillatory means, and circuit closing meansvibrating separately from the oscillatory means for intermittentlyclosing the circuit of the electromagnetic means, the circuit closingmeans being operated by the electromagnetic means and its closing beingautomatically synchronized with the oscillatory means.

3. Motor apparatus comprising an oscillatory member, means for supplyingenergy to said member for oscillating it, and oscillatory meansvibrating separately from the oscillatory member for controlling thesupply of energy, the oscillatory means being so tuned and controlledwith respect to the oscillatory member as recurrently to supply energyto the member at the proper frequency to oscillate it regularly.

4. Motorl apparatus comprising an oscillatory member, means forsupplying energy to said member for oscillating it, a device renderedoperative by said energy, and oscillatory means oscillating separatelyfrom the oscillatory member tuned to the same periodicity as theoscillatory member and controlled by the said device for. intermittentlyinterrupting the supply of, energy, thereby to cause the oscillatorymember to oscillate in synchronism with the oscillatory means. Y

5. Motor apparatus comprising a driving member, a driven rotatingmember, a iiexible band operatively connecting the driving member withthe' driven member in such manner that the operation of the drivingmember sets up waves in the flexible member, and tuned oscillatory meansoscillating separately from the driving member Jfor recurrentlysupplying energy to the driving member at a uniform rate, and a commonoperating coil for said member and said means.

6. Motor 'apparatus comprising an oscillatory driving member, a circuitfor supplying energy, oscillatory means independent of the oscillatorydriving member for intermittently closing the circuit, and anelectromagnet responsive to the energy for actuating the oscillatorymember and means.

Motor apparatus comprising an oscillatory driving member, a circuit forsupplying energy, oscillator means independent of the oscillatory drivmgmember for intermittently closing the circuit, and an electromagnetresponslve to the energy for actuating the oscillatory member and means,the oscillatory member and means being tuned to oscillate insynchronism.

8. Motor apparatus comprising a vibratory member having two Jfree endsadapted to vibrate in synchronism, means for deriving power from one ofthe ends, said means comprising a iiexible band connected to one end ofsaid member, a driven member in operative engagement with said band, andmeans for supplying energy to the vibratory member to vibrate it, thesupply means being intermittently rendered operative by the otherI free`end of the vibratory member. v

9. Motor apparatus comprising a vibratory member 1n the form of a tuningfork, means for driving apparatus with one prong of the fork, said meanscomprising a flex.- ible band normally under tension and operativelyconnecting one prong of said fork to a pulley to be rotated, means forsupplying energy to the vibratory member to vibrate it, and meanscontrolled by the other prong of the fork for interrupting the supply ofenergy at recurrent periods corresponding to the period of vibration' ofthe tuning fork.

l0. yMotor apparatus comprising a vibratory memberl mounted intermediateits ends so that the ends vibrate in synchronism, means for supplyingenergy to the vibratory member to vibrate both ends, a flexible bandassociated with one of the vibrating ends of the member so as to bevibrated thereby, a pulley yaround which said fiexible band is wrappedand means controlled by the other end of the member for recurrentlyapplying the energy to the members, thereby continuously to vibrate saidends.

1l. Motor apparatus comprising a vibratory member in the form of atuning fork, the free ends of Which have at least approximately the sameperiod so as to vibrate in synchronism, electromagnetic means forvibrating said free ends', means including a circuit for supplyingcurrent to the electromagnetic means, a flexible band arranged to bedriven by one vibrating end of said member, a pulley around which aportion of said band is Wrapped to drive said pulley when said tuningfork is vibrated, and means associated with the other vibrating end ofsaid member so as to interrupt the circuit of the current supply duringa portion of each vibration of the vibrating ends for intermittentlyenergizing the electromagnetic means at the proper frequencycontinuously to vibrate said members.

Signed by me at Montreal, Canada, this first day of December, 1916.

LESLIE R. MCDONALD.

